RU2652225C2 - Substrate for security papers and method of manufacturing same - Google Patents

Abstract

FIELD: production of paper; production of cellulose.

SUBSTANCE: invention relates to a substrate for security documents, such as banknotes, and a method for manufacturing same. Said substrate (S) comprises one or more paper layers (11, 12) and polymer layer (20) which is made to adhere to a side of at least one of the paper layers (11, 12). Polymer layer (20) is substantially transparent in at least one region of substrate (S) which is not covered by one or more paper layers (11, 12) so as to form a substantially transparent window (W) in substrate (S) which is formed and closed by polymer layer (20). Polymer layer (20) exhibits in the region of window (W) thickness (T) which is greater than thickness (t) of polymer layer (20) outside of the region of window (W). Thickness (T) of polymer layer (20) in the region of window (W) is substantially equal to the added thickness of paper layer or layers (11, 12) and of polymer layer (20) outside of the region of window (W) so that substrate (S) exhibits a substantially uniform and constant thickness (T). Substrate (S) further comprises micro-optical structure (30), in particular a lens structure, which is disposed in the region of window (W) on at least one side of polymer layer (20).

EFFECT: invention provides security documents with enhanced dynamic and/or optically variable effects and higher degree of protection thereof.

20 cl, 6 dwg

Description

Technical field

The present invention generally relates to a substrate for security papers, in particular for banknotes and similar documents with a high degree of security, and a method for its manufacture.

BACKGROUND OF THE INVENTION

In the field of security printing, in particular for the production of banknotes, many types of substrates are used, including (i) paper substrates, which are usually made of cotton fibers, (ii) plastic or polymer substrates, which are made of a special polymer material (such as biaxially oriented polypropylene, or "BOPP") coated on both sides with white opaque layers, as well as (iii) the so-called hybrid or multilayer substrates, which combine paper and polymer substrates in one medium materials or layers.

One of the special features of polymer substrates, an example of which is a commemorative banknote of Australian $ 10, 1988, is to provide a transparent window formed by a region of the substrate in which white opaque layers on both sides are not applied so that some of the polymer material remains unclouded. This window portion is typically used to provide additional protection by forming or applying features such as embossments, printed images, and foil elements such as optically variable devices (OVDs) in the window.

Similar window features can be created in paper substrates and hybrid substrates, provided that the corresponding paper layer (s) are provided with corresponding openings. In the case of hybrid substrates, an additional polymer layer can be used to close the window. In the case of paper substrates, the window-forming hole (which is obtained, for example, by cutting), as a rule, must be covered with a special layer of material, such as foil, which is laminated on top of the window or otherwise embedded in the paper during manufacture. This process can be carried out at a paper mill or, more preferably, at a printing house in accordance with the methods explained in published international patent applications No. WO 2008/104904 A1, WO 2009/112989 A1 and WO 2010/001317 A1.

A potential problem with paper-based window features is the fact that the hole in the paper layer (s) is contaminated and causes roughness and unevenness in the thickness of the substrate, which can adversely affect the processing of the substrate by in-line processing equipment and transportation by him. In international publication No. WO 2005/116335 A1, a solution is proposed which consists in filling a hole with a transparent filler, but this solution requires additional technological steps after applying a foil designed to cover the window area. In addition, adequate binding of the transparent filler within the opening becomes problematic with this solution.

There is another tendency in the security printing industry to combine micro-optical structures, such as lens structures, with printed images, which are provided under and in agreement with micro-optical structures, so as to create sophisticated dynamic and / or optically variable effects. An example of such a combination of a lens structure with a printed image is disclosed in International Publication No. WO 2007/020048 A2. This document says that the dynamic and / or optically variable effect is enhanced and optimized by maximizing the distance between the micro-optical structure and the printed image, namely by using the entire thickness of the substrate material.

Therefore, there is a need for an improved substrate and method for its manufacture.

SUMMARY OF THE INVENTION

The general objective of the invention is to improve the known substrates used for the manufacture of security documents, in particular banknotes.

An additional objective of the invention is to provide such a substrate, which expediently includes a micro-optical structure based on the window.

These goals are achieved thanks to the invention, which is defined by the formula.

Further preferred embodiments of the invention are the subject of the dependent claims and are discussed below.

A brief description of the graphic materials

Other features and advantages of the present invention will become clearer after reading the following detailed description of embodiments of the invention, which are given solely as non-limiting examples and are illustrated by the accompanying graphic materials, where:

FIG. 1 is a schematic illustration of the back of a security document in the form of a banknote that contains a substrate according to the invention and generally illustrates the first, second and third embodiments of the invention;

FIG. 2 is a schematic sectional view of the banknote of FIG. 1 taken along line AA in accordance with a first embodiment of the invention;

FIG. 3 is a schematic sectional view of the banknote of FIG. 1 taken along line AA in accordance with a second embodiment of the invention;

FIG. 4 is a schematic sectional view of the banknote of FIG. 1 taken along line AA in accordance with a third embodiment of the invention;

FIG. 5 is a schematic sectional view of a banknote in accordance with a fourth embodiment of the invention; and

FIG. 6 is a schematic sectional view of a banknote in accordance with a fifth embodiment of the invention.

Detailed Description of Embodiments

The present invention will be described in the context of a single application of a substrate for making banknotes. However, it should be understood that the backing of the invention can be used to produce a variety of other security documents, such as visas, passports or similar travel documents or identification cards. It should be understood that the substrate of the invention can take any appropriate form of the substrate, which is suitable for processing on printing and technological equipment, which is usually used for the manufacture of security documents, namely provided in the form of separate sheets or continuous tape. Therefore, in the context of the present invention, the term “substrate” means a sheet or tape material of any shape, including individual sheets or continuous tape, such as those used for the manufacture of security documents, as well as a separate document substrate made of such sheets or tape, such as individual banknotes.

In FIG. 1 shows a separate security document in the form of a banknote containing a substrate according to the invention. It is typical for the art to produce banknotes in the form of separate sheets or consecutive parts of a continuous tape, and on these sheets or parts there is a marking of the positions of individual bills, which are processed into (i.e. cut into) individual documents at the end of the manufacturing process. Therefore, it should be understood that the corresponding substrate in the form of a sheet or tape as a whole contains multiple repetitions of the banknote substrate, as shown in FIG. one.

FIG. 1 will be used to illustrate and describe the first, second, and third embodiments of the invention, the substrate being indicated by S, S *, S **, Sa, and Sb, respectively, to distinguish between these embodiments. As shown in FIG. 1, in the substrate S (S *, S **, Sa, Sb) there is a window (window part) W, i.e. a part of the substrate material, which is essentially transparent, at least partially, and which is formed and covered by a polymer layer. Although in FIG. 1 shows only one window, it is possible to provide several windows of any desired shape.

As will become clear after reading the description below, the window is covered with a polymer layer denoted by reference numeral 20 in the context of the first embodiment and reference numerals 20 'and 20' 'in the context of the second and third embodiments, respectively. This polymer layer can be made of any suitable substantially transparent polymer material, such as biaxially oriented polypropylene (BOPP). The polymer layer may also consist of a single uniform layer of polymer material or of a layered material comprising two or more layers of polymer material.

The polymer layer 20 (20 ', 20' ', 20 *, 20 **) can extend only over part of the substrate area S (S *, S **, Sa, Sb), as shown schematically by dashed lines in FIG. 1, which indicate a strip of polymer material extending across the width of the substrate S (S *, S **, Sa, Sb) of the banknote. However, the polymer layer may take any other form, suitably covering at least the area of the window portion W, such as the shape of the strip or patch. In the context of the invention, the polymer layer 20 (20 ', 20' ', 20 *, 20 **) can preferably extend over the entire area of the substrate S (S *, S **, Sa, Sb), which simplifies the manufacturing steps.

As shown further in FIG. 1, a micro-optical structure is formed in the window region W, denoted by 30, 40 or 50 in the context of the first, second or third embodiment of the invention, respectively. This micro-optical structure 30 (40, 50) is preferably a lens structure, i.e. a structure that contains several individual lens elements, such as semi-cylindrical or hemispherical lens elements. For clarity, we assume that the micro-optical structure 30 (40, 50) consists in this example of several semi-cylindrical lens elements oriented horizontally in FIG. 1. Other micro-optical structures are possible, such as Fresnel lens structures or even more complex structures. In the context of the invention, the term “micro-optical structure” means any non-planar surface in or on the surface of the substrate S (S *, S **, Sa, Sb) that provides or creates an optical change in appearance when viewed through this non-planar surface. The microoptical structure 30 (40, 50) can pass only partly or throughout the region of the window W or even go beyond the window W, depending on the chosen design and how the microoptical structure 30 (40, 50) is formed on the substrate S ( S *, S **, Sa, Sb).

Further in FIG. 2, which illustrates a first embodiment of the invention, a section of the banknote of FIG. 1 taken along the line A-A through the substrate S and the window region W, where the polymer layer 20 and the micro-optical structure 30 are visible. As shown schematically, in the okneobrazuyuschim part W, the polymer layer 20 has a thickness T (preferably about 100 microns), which is greater thickness t of the polymer layer 20 outside the window region W. Further, as shown in FIG. 2, the first and second paper layers 11, 12 are provided on each side of the polymer layer 20, and these paper layers 11, 12 do not cover the region of the window W. In other words, the polymer jar 20 is sandwiched between the first and second paper layers 11, 12 and in the region Windows W contains parts protruding in the direction of both sides I, II of the substrate S, and is substantially transparent in at least one region of the substrate (S; S *; S **; Sa; Sb) that is not covered by one or more paper layers (11, 12; 15; 11 *, 12 *; 15 *).

As shown in FIG. 2, the thickness T of the polymer layer 20 in the region of the window W is essentially equal to the sum of the thicknesses of the paper layers 11, 12 and the polymer layer 20 outside the region of the window W. Thus, the substrate S has a substantially uniform and constant thickness T, it being understood that the thickness micro-optical structure 30 is not taken into account.

For clarity, the micro-optical structure 30 in the region of the window W is preliminarily deposited by embossing directly on the side of the polymer layer 20, namely, the side coinciding with the upper side I of the substrate S. In other words, according to this first embodiment, the micro-optical structure 30 is an integral part of the polymer layer 20. However, the micro-optical structure can be formed or deposited not only by direct embossing on the polymer layer, as will become clear from the description of the second and third variations comrade embodiment.

In FIG. 3 shows a cross section of the banknote of FIG. 1, along the same line AA, according to a second embodiment of the invention. For clarity, the substrate is indicated by S * in this new example. The second embodiment shown in FIG. 3 differs from the first embodiment shown in FIG. 2 in that the micro-optical structure indicated by 40 is pre-embossed on the side of the foil member 45, which is applied, preferably by hot stamping, on the side of the polymer layer, indicated by 20 '.

In FIG. 4 shows a cross section of the banknote of FIG. 1, along line AA, according to a third embodiment of the invention. This new embodiment differs from the previous embodiments described above in that the polymer layer 20 ″ is open on one side (namely, on the upper (first) side I in this example) of the substrate, indicated by S **, and is substantially flat the surface is all over this side I. (The same applies to the embodiment shown in Fig. 6, where the polymer layer 20 ** is open on one side (namely, on the upper (first) side I in this example) of the substrate indicated by the symbol Sb, and has a substantially flat surface throughout this side I.) A paper layer 15 is provided on the other side of the polymer layer 20 ″ where a protruding part is formed in the region of the window W. Like the paper layer 12 of the embodiments of FIG. 2 and 3, a paper layer 15 is provided on the underside of the polymer layer 20 ″ so as not to cover the window region W.

The thickness T of the polymer layer 20 ″ in the region of the window W again essentially equals the sum of the thicknesses of the paper layer 15 and the polymer layer 20 ″ outside the region of the window W, whereby the substrate S ** produces a substantially uniform and constant thickness T.

The micro-optical structure, indicated in this third embodiment by reference numeral 50, is formed by embossing on the side of a layer of material 55 (for example, a printing layer), which is applied, preferably before embossing, on the side of the polymer layer 20 ''. However, it should be understood that the micro-optical structure 50 can be pre-applied by embossing directly on the side (upper or lower side) of the polymer layer 20 ″ (as in the first embodiment) or pre-applied by embossing on the side of the foil element that is applied, preferably by hot stamping, on the side of the polymer layer 20 '' (as in the second embodiment).

It may be convenient to additionally apply a lightproof layer over the polymer layer 20 ″ of FIG. 3 (except for the window region W), as in the case of known polymer substrates.

It should be noted that the first and second paper layers 11, 12 of the embodiments of FIG. 2 and 3 and the paper layer 15 of the embodiment of FIG. 4 may in each case consist of a single paper layer or of a laminate comprising several layers, including at least one paper layer.

As shown in the examples of the above embodiments, the advantage of the substrate of the invention is that the substrate has a substantially uniform and constant thickness, especially in the window region, whereby pollution problems are solved. In addition, the polymer layer 20 (20 ', 20' ', 20 *, 20 **) in the region of the window W forms a substantially uniform and flat region that enhances the optical effect of the micro-optical structure 30 (40, 50). The near-forming part of the polymer layer 20 (20 ', 20' ', 20 *, 20 **) is particularly preferred because it provides adequate support for printing the image on the substrate side S (S *, S **, Sa, Sb) opposite on the side where the micro-optical structure 30 (40, 50) is located, due to which the optimal optically variable effect is produced if we consider the window W from the upper side I of the substrate S (S *, S **, Sa, Sb).

In FIG. 5 and 6 show further embodiments of the invention, emphasizing that the thickness of the polymer layer indicated by 20 *, respectively. 20 **, there can be a smooth transition to the thickness of the window region W, namely a smooth transition from the thick region of the polymer layer 20 *, 20 ** forming the window W to a thinner region of the polymer layer 20 *, 20 ** outside the window region W The paper layers 11 *, 12 * in FIG. 5 and the paper layer 15 * in FIG. 6, a gradual decrease in thickness is also observed when approaching the window region W.

The micro-optical structures 60, 70 shown in FIG. 5, 6 are similar to the micro-optical structure 30 of FIG. 2. Alternatively, these micro-optical structures 60, 70 can be formed as in the alternative examples of FIG. 3 and 4.

As for the manufacture of the substrate, the method requires:

a) providing a polymer layer containing at least one okneobrazuyuschey part, the thickness of which is greater than the thickness of the polymer layer outside the okneobrazuyuschego part;

b) providing one or more paper layers so that the polymer layer is forced to adhere to the side of at least one of the paper layers, and that the resulting substrate has a substantially uniform and constant thickness; and

c) providing a micro-optical structure on at least one side of the near-forming part of the polymer layer.

Methods known in this capacity in the art can be used to ensure that the polymer layer is appropriately bonded and adhered to the paper layer (s).

Various modifications and / or improvements can be made in relation to the above embodiments without going beyond the scope of the invention defined by the attached claims. In particular, as already mentioned, the invention is not limited to any particular shape of the substrate, but is preferably made in the form of separate sheets or continuous tape.

List of reference numbers used in this document (if any)

S substrate, for example, a banknote or banknote sheet (first embodiment)

S * substrate, for example, a banknote or banknote sheet (second embodiment)

S ** substrate, for example, a banknote or banknote sheet (third embodiment)

Sa substrate, for example, a banknote or banknote sheet (fourth embodiment)

Sb substrate, for example, a banknote or banknote sheet (fifth embodiment)

W window / window forming part of the polymer layer 20, 20 ', 20' ', 20 *, 20 **

I first (upper) side of the substrate S, S *, S **, Sa, Sb

II second (lower) side of the substrate S, S *, S **, Sa, Sb

11 first (upper) paper layer (first and second embodiments)

12 second (lower) paper layer (first and second embodiments)

11 * first (top) paper layer (fourth embodiment)

12 * second (lower) paper layer (fourth embodiment)

15 (lower) paper layer (third embodiment)

15 * (bottom) paper layer (fifth embodiment)

20 polymer layer (first embodiment)

20 'polymer layer (second embodiment)

20 '' polymer layer (third embodiment)

20 * polymer layer (fourth embodiment)

20 ** polymer layer (fifth embodiment)

30 micro-optical structure, for example, a lens structure, previously deposited by embossing on okobrazuyuschie part W of the polymer layer 20 (first embodiment)

40 micro-optical structure, for example, a lens structure (second embodiment)

45 foil element pre-stamped with micro-optical embossing 40

50 micro-optical structure, for example, a lens structure (third embodiment)

55 layer (for example, a printing layer), which is deposited on the back forming part W of the polymer layer 20 ″ and then embossed to form a micro-optical structure 50

60 micro-optical structure, for example, a lens structure (fourth embodiment)

70 micro-optical structure, for example, a lens structure (fifth embodiment)

T the thickness of the substrate S, S *, S **, Sa, Sb and okobrazuyushchego part W of the polymer layer 20, 20 ', 20' ', 20 *, 20 **

t the thickness of the polymer layer 20, 20 ', 20' ', 20 *, 20 ** outside okneobrazuyuschego part W

Claims (26)

1. A substrate (S; S *; S **; Sa; Sb) for security documents containing one or more paper layers (11, 12; 15; 11 *, 12 *; 15 *) and a polymer layer (20; 20 '; 20ʺ; 20 *; 20 **), made with the possibility of gluing to the side of at least one of the paper layers (11, 12; 15; 11 *, 12 *; 15 *), the polymer layer (20; 20' ; 20ʺ; 20 *; 20 **) is essentially transparent in at least one region of the substrate (S; S *; S **; Sa; Sb), which is not covered by one or more paper layers (11, 12 ; 15; 11 *, 12 *; 15 *), so that, in the substrate (S; S *; S **; Sa; Sb), an essentially transparent window (W) is formed, which is formed o and covered with a polymer layer (20; 20 '; 20ʺ; 20 *; 20 **), where the polymer layer (20; 20 '; 20ʺ; 20 *; 20 **) in the window region (W) has a thickness (T) that is greater than the thickness (t) of the polymer layer (20; 20'; 20ʺ; 20 *; 20 **) outside the window area (W), where the thickness (T) of the polymer layer (20; 20 '; 20ʺ; 20 *; 20 **) in the region of the window (W) is essentially equal to the sum of the thicknesses of one or more paper layers (11, 12; 15; 11 * , 12 *; 15 *) and the polymer layer (20; 20 '; 20ʺ; 20 *; 20 **) outside the window area (W), so that the substrate (S; S *; S **; Sa; Sb) there was essentially uniform and constant thickness (T), and where the substrate (S; S *; S **; Sa; Sb) further comprises a micro-optical structure (30; 40; 50; 60; 70) located in the window region (W) on at least one side of the polymer layer (20 ; 20 '; 20ʺ; 20 *; 20 **). 2. The substrate (S; S *; S **; Sa; Sb) according to claim 1, where the polymer layer (20; 20 '; 20ʺ) extends over the entire area of the substrate (S; S *; S **; Sa; Sb). 3. The substrate (S; S *; S **; Sa; Sb) according to claim 1, where the polymer layer (20; 20 '; 20ʺ; 20 *; 20 **) passes only over part of the surface of the substrate (S; S *; S **; Sa; Sb). 4. The substrate (S; S *; S **; Sa; Sb) according to claim 3, where the polymer layer (20; 20 '; 20ʺ; 20 *; 20 **) has the form of a strip or patch of polymer material. 5. The substrate (S; S *; Sa) according to any one of paragraphs. 1-4, where the polymer layer (20; 20 '; 20 *) is sandwiched between at least the first and second paper layers (11, 12; 11 *, 12 *) and in the region of the window (W) contains parts protruding in the direction both sides (I, II) of the substrate (S; S *; Sa). 6. The substrate (S **; Sb) according to any one of paragraphs. 1-4, where the polymer layer (20ʺ; 20 **) is open on the first side (I) of the substrate (S **; Sb) and has on this first side (I) a substantially flat surface. 7. The substrate (S; Sa; Sb) according to any one of paragraphs. 1-4, where the micro-optical structure (30; 60; 70) in the window region (W) is preliminarily deposited by embossing directly on the side of the polymer layer (20; 20 *; 20 **). 8. The substrate (S *) according to any one of paragraphs. 1-4, where the micro-optical structure (40) in the region of the window (W) is pre-applied by embossing on the side of the foil element (45) applied to the side of the polymer layer (20 '). 9. The substrate (S *) according to claim 8, where the foil element (45) is deposited by hot stamping on the side of the polymer layer (20 '). 10. The substrate (S **) according to any one of paragraphs. 1-4, where the micro-optical structure (50) in the region of the window (W) is formed by embossing on the side of the layer of material (55) deposited on the side of the polymer layer (20ʺ). 11. The substrate (S **) according to claim 10, where the layer of material (55) is deposited on the side of the polymer layer (20ʺ) by printing. 12. The substrate (S; S *; S **; Sa; Sb) according to any one of paragraphs. 1-4, where the thickness (T) of the substrate (S; S *; S **; Sa; Sb) and the polymer layer (20; 20 '; 20ʺ; 20 *; 20 **) in the window region (W) is about 100 microns. 13. The substrate (Sa; Sb) according to any one of paragraphs. 1-4, where the thickness of the polymer layer (20 *; 20 **) contains a smooth transition to the window region (W). 14. The substrate (S; S *; S **; Sa; Sb) according to any one of paragraphs. 1-4, where the micro-optical structure (30; 40; 50; 60; 70) is a lens structure. 15. A method of manufacturing a substrate (S; S *; S **; Sa; Sb) according to claim 1, comprising the steps of: a) providing at least one polymer layer (20; 20 '; 20ʺ; 20 *; 20 **) containing at least one okobrazuyuschey part (W), the thickness (T) of which is greater than the thickness (t) of the polymer layer (20 ; 20 '; 20ʺ; 20 *; 20 **) outside of the forming part (W); b) providing one or more paper layers (11, 12; 15; 11 *, 12 *; 15 *) so that the polymer layer (20; 20 '; 20ʺ; 20 *; 20 **) adheres to the side of at least at least one of the paper layers (11, 12; 15; 11 *, 12 *; 15 *), and so that the resulting substrate (S; S *; S **; Sa; Sb) is essentially uniform and constant thickness (T); and c) providing a micro-optical structure (30; 40; 50; 60; 70), in particular a lens structure, on at least one side of the near-forming part (W) of the polymer layer (20; 20 '; 20ʺ; 20 *; 20 **) . 16. The method according to p. 15, where the micro-optical structure (30; 60; 70) is pre-applied by embossing directly on the side of the okneobrazuyuschie part (W) of the polymer layer (20; 20 *; 20 **). 17. The method according to p. 15, where the micro-optical structure (40) is pre-applied by embossing on the side of the foil element (45) deposited on the side of the backing part (W) of the polymer layer (20 '). 18. The method according to p. 17, where the foil element (45) is deposited by hot stamping on the side of the forming part (W) of the polymer layer (20 '). 19. The method according to p. 15, where the micro-optical structure (50) is formed by embossing the sides of the layer of material (55), deposited on the side okobrazuyuschego part (W) of the polymer layer (20ʺ). 20. The method according to any one of paragraphs. 15-19, where the thickness (T) of the substrate (S; S *; S **; Sa; Sb) and the forming part (W) of the polymer layer (20; 20 '; 20ʺ; 20 *; 20 **) is about 100 microns.

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